Seamless tube drawing tool



8, 1953 D. P. GREMLING 2,649,002

SEAMLESS TUBE DRAWING TOOL Filed Aug. 10, 1950 FIIJ IN VENT OR.

Wmwvmz P firemZz'n ATTORNEYS Patented Aug. 18, 1953 UNITED STATES EATENTOFFICE SEAMLESS TUBE DRAWING TOOL Donovan P. Gremling, Shelby, OhioApplication August 10, 1950, Serial N 0. 178,687

3 Claims. (01. 80-13) This invention relates to machines for drawingseamless tubing by the axial rolling process wherein billets are forcedby a ram over a point with a pair of pressure rollers traveling aroundthe point for forming the billets into a seamless tube, and inparticular this invention relates to an improved mounting for the pointsover which the billets are forced, wherein the point is journaled on atubular spindle that telescopes over a mandrel with a ball thrustbearing behind the point to facilitate rotation thereof and with acooling water opening extended into the point to hold the temperature ofthe point comparatively low.

The purpose of this invention is to reduce the friction resulting fromrotation of comparatively long mounting sleeves on which points overwhich billets are forced are carried whereby the points rotate morefreely and consequently wear longer.

In the conventional type of points over which billets are forced to formseamless tubing the points are provided on spindles and the length ofthe spindles increases the bearing surface area and at the extreme heatthe rotation of the points is restricted. To obtain efiicient operationit is desired that the point rotate as freely as possible and toaccomplish this purpose this invention contemplates separating thepoints from the spindle and rotatably mounting the points on a tubularshaft with a ball thrust bearing behind the points so that the pointsonly rotate and the rotating part is journaled against a ball thrustbearing to reduce the friction where the resulting force is applied.

The object of this invention is, therefore, to provide means for forminga point over which billets of seamless tube rolling mills are drivenwhereby the point, only, rotates and whereby means is provided forreducing the friction and temperature.

Another object of the invention is to provide a mounting for points ofseamless tube mills wherein a cushion is provided for taking the shockload from the thrust bearing and associated parts.

A further object of the invention is to provide an improved mounting forthe point of seamless tube mills over which billets are driven betweenpairs of rolls, which is of a comparatively simple and economicalconstruction.

With these and other objects and advantages in view the inventionembodies a conical shaped point rotatably mounted on a tubular shaftwith the shaft extended from a sleeve telescoping on a spindle, with aball thrust bearing between the point and shoulder of the sleeve andwith a spring between the end of the sleeve and a shoulder of thespindle.

Other features and advantages of the invention will appear from thefollowing description taken in connection with the drawings wherein:

Figure 1 is a longitudinal section through a point of a seamless tubemill showing the point entering a billet being driven over the point andshowing a pair of rolls that travel around the point to form the billetinto a tube.

Figure 2 is a cross section through the point taken on line 2-2 ofFigure 1.

Referring now to the drawings wherein like reference characters denotecorresponding parts the improved seamless tubing forming point of thisinvention includes a conical shaped point it, a shaft l l on which thepoint is mounted, a sleeve l2 from which the shaft extends, a ballthrust bearing [3, a mandrel I4 and a spring l5 between the inner end ofthe sleeve and a shoulder It on the mandrel.

It will be understood that although the point It is illustrated with asubstantially pointed outer end to provide a piercing point, the pointmay also be formed to provide a reeling point, and the slope of thepoint may be changed as may be desired.

In the design shown the point it is provided with a bore I! in which thetubular shaft H is positioned and a bushing [8 may be provided at theend of the shaft. The bushing [8 may be replaced with a bushing of adifferent size as the point wears. The base of the point is providedwith a oounterbore 19 to provide clearance for a set screw 20 that isthreaded into the shaft H to hold the ball thrust bearing Is in positionagainst a shoulder 2| and on a bearing surface 22 between the shaft Hand sleeve 12.

The sleeve [2 is also provided with a bore 229 in which the end 23 ofthe mandrel 54 extends and, as illustrated in Figure 1 the mandrel isprovided with an elongated slot 2 3 into which the inner end of a setscrew 25, threaded in the sleeve l2 extends to key the sleeve to thespindle.

A space 26 is provided between the end of the spindle and inner end ofthe bore of the sleeve whereby the sleeve telescopes on the spindleproviding a reciprocating action, thereby forming a cushion to relievethe thrust bearing [3 of the shock load.

The spindle is provided with an opening 27 through which cooling waterpasses to the bore 28 of the shaft ll upon which the point is iscarried.

With the parts formed in this manner a billet;

be made in the design and arrangement of the" parts without departingfrom the spirit of the invention.

What is claimed is: V v 1. In a seamless tube forming tool, thecombination which comprises a mandrel having areduced end portion and abore therethroug-h, a shoulder on the outer surface of the mandrelspaced from the end of the reduced end portion and a longitudinallydisposed slot extended inwardly from the outer surface of the reducedend portion, a sleeve having an extended tubular shaft at one endthereof slidably mounted on the reduced end portion of the' mandrel,resilient means between the end of the sleeve and shoulder of themandrel, a point for receiving a billet journaled on the tubular shaftof the sleeve, and a ball thrust bearing positioned between the base ofthe point and shoulder at the end of the sleeve, said sleeve having aset screw extended into the longitudinally disposed slot of the mandrelto limit the longitudinal movement of the sleeve on the reduced endportion.

2. In a seamless tube forming tool, the combination which comprises amandrel having" a reduced end portion and a bore therethrough, ashoulder on the outer surface of the mandrel spaced from the end of thereduced end portion and a longitudinally disposed slot extended inwardlyfrom the outer surface of the reduced end portion, a sleeve having anextended tubular shaft at one end thereof slidably mounted on thereduced end portion of the mandrel, resilient means between the end ofthe sleeve and shoulder of the mandrel, a point for receiving a billetjournaled on the tubular shaft of the sleeve, a ball thrust bearingpositioned between the base of the point and shoulder at the end of thesleeve, said sleeve having a set screw extended into the longitudinallydisposed slot of the mandrel to limit the longitudinal movement of thesleeve on the reduced end portion, and a pushing in the point positionedagainst the end of the tubular shaft.

3. In a seamless tube forming tool, the combination which comprisesmandrel having a reduced end portion and a bore therethrough, a shoulderon the outer surface of the mandrel spaced from the end of the reducedend portion and a longitudinally disposed slot extended inwardly fromthe outer surface of the reduced end portion, a sleeve having anextended tubular shaft at one" end thereof slidably mounted on thereduced end portion of the mandrel, resilient means between the end ofthe sleeve and shoulder of the mandrel, a point for receiving a billetjournaled on the tubular shaft of the sleeve, a ball thrust bearingpositioned between the base of the point and shoulder at the end of thesleeve, said sleeve having a set screw extended into the longitudinallydisposed slot of the mandrel to limit the longitudinal moveiiintof thesleeve on the reduced end portion, a bushing in the point positionedagainst the end or the tubular shaft, said point having a couriterboi onthe base and a set screw threaded in themselar shaft for securing theball thrust bearing in position on the sleeve, I v H DONOVAN P.GREMLING.

References Cited in the file of this patent UNITED STATES PA'I EN'I SBark et a1. July 21, 1931 Becker Die'scher Jan. 29', 1935 Indge' Aug5,1941

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